Gas containers, such as gas bottles, are common in a wide variety of industries. For instance, in the medical industry, gas containers are typically filled with oxygen, carbon dioxide and the like, for a variety of medical uses. The gas containers are provided with a standardized valve arrangement generally at the top thereof to allow discharge of the gas from the container during use, as well as to permit filling of the container with additional gas. The valve arrangements for the gas containers are standardized to allow a filling apparatus to mate with each valve arrangement. The filling apparatus is generally constructed so as to fasten onto the valve arrangement and allow a gas to be introduced into the container through the filling apparatus and valve arrangement after a valve on the valve arrangement is manually opened, thereby enabling filling of the container.